We know it makes good sense to focus on improving literacy in children and younger people in the workforce because this will improve their lives, the country's economic productivity, and have flow-on effects to older age. But the structure of our population is changing. Does New Zealand need to know more about literacy in older age so that, if needed, help can be offered to improve the quality of the rest of an older person's life?

There is some good data available about literacy for people aged 65 and younger but the reliability of the data is weakest where literacy rates appear to be the worst. This is mostly because sample sizes were too small.

The Ministry of Education is aware of this and is planning to over-sample those parts of the population when it next completes a literacy survey (scheduled for 2014). This should result in better quality data, and make it easier to work out whether actions to improve literacy are working.

As we work through the rest of the Madrid indicators, we're finding that sample sizes are a common problem for government departments. It can be expensive for departments to routinely collect enough data to analyse it by age, sex, and ethnicity. On the other hand, not having the data can make it more difficult to devise policy and services, and to assess their effectiveness.